/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield * * This library is open source and may be redistributed and/or modified under * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or * (at your option) any later version. The full license is in LICENSE file * included with this distribution, and on the openscenegraph.org website. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * OpenSceneGraph Public License for more details. */ #ifndef OSG_TRANSFORM #define OSG_TRANSFORM 1 #include #include namespace osg { /** compute the matrix which transforms objects in local coords to world coords, * by accumulating the Transform local to world matrices along the specified node path.*/ extern SG_EXPORT Matrix computeLocalToWorld(NodePath& nodePath); /** compute the matrix which transforms objects in world coords to local coords, * by accumulating the Transform world to local matrices along the specified node path.*/ extern SG_EXPORT Matrix computeWorldToLocal(NodePath& nodePath); /** compute the matrix which transforms objects in local coords to world coords, * by accumulating the Transform local to world matrices along the specified node path * the supplied initialial camera modelview .*/ extern SG_EXPORT Matrix computeLocalToEye(const Matrix& modelview, NodePath& nodePath); /** compute the matrix which transforms objects in world coords to local coords, * by accumulating the Transform world to local matrices along the specified node path * the inverse of the supplied initialial camera modelview.*/ extern SG_EXPORT Matrix computeEyeToLocal(const Matrix& modelview, NodePath& nodePath); /** A Transform is a group node for which all children are transformed by * a 4x4 matrix. It is often used for positioning objects within a scene, * producing trackball functionality or for animation. * * Transform itself does not provide set/get functions, only the interface * for defining what the 4x4 transformation is. Subclasses, such as * MatrixTransform and PositionAttitudeTransform support the use of an * osg::Matrix or a osg::Vec3/osg::Quat resprectively. * The Transform node can be customized via the ComputeTransfromCallback * which can be attached to the node. This might be used to convert from * internal representations of the transformation into generic osg::Matrix * objects which are used during scene grpah traversal, such as * CullTraversal and IntersectionTraversal. * * Note: if the transformation matrix scales the subgraph then the normals * of the underlying geometry will need to be renormalized to be unit * vectors once more. This can be done transparently through OpenGL's * use of either GL_NORMALIZE and GL_SCALE_NORMALIZE modes. For further * background reading see the glNormalize documentation in the OpenGL * Reference Guide (the blue book). To enable it in the OSG, you simply * need to attach a local osg::StateSet to the osg::Transform, and set * the appropriate mode to ON via * stateset->setMode(GL_NORMALIZE, osg::StateAttribute::ON); */ class SG_EXPORT Transform : public Group { public : Transform(); /** Copy constructor using CopyOp to manage deep vs shallow copy.*/ Transform(const Transform&,const CopyOp& copyop=CopyOp::SHALLOW_COPY); META_Node(osg, Transform); virtual Transform* asTransform() { return this; } virtual const Transform* asTransform() const { return this; } virtual MatrixTransform* asMatrixTransform() { return 0; } virtual const MatrixTransform* asMatrixTransform() const { return 0; } virtual PositionAttitudeTransform* asPositionAttitudeTransform() { return 0; } virtual const PositionAttitudeTransform* asPositionAttitudeTransform() const { return 0; } enum ReferenceFrame { RELATIVE_TO_PARENTS, RELATIVE_TO_ABSOLUTE }; /** Set the transform's ReferenceFrame, either to be relative to its * parent reference frame, or relative to an absolute coordinate * frame. RELATIVE_TO_PARENTS is the default. * Note: setting the ReferenceFrame to be RELATIVE_TO_ABSOLUTE will * also set the CullingActive flag on the transform, and hence all * of its parents, to false, thereby disabling culling of it and * all its parents. This is neccessary to prevent inappropriate * culling, but may impact cull times if the absolute transform is * deep in the scene graph. It is therefore recommend to only use * absolute Transforms at the top of the scene, for such things as * heads up displays. */ void setReferenceFrame(ReferenceFrame rf); ReferenceFrame getReferenceFrame() const { return _referenceFrame; } /** Callback attached to an Transform to specify how to compute the * modelview transformation for the transform below the Transform * node. */ struct ComputeTransformCallback : public virtual osg::Referenced { /** Get the transformation matrix which moves from local coords * to world coords.*/ virtual bool computeLocalToWorldMatrix(Matrix& matrix,const Transform* transform, NodeVisitor* nv) const = 0; /** Get the transformation matrix which moves from world coords * to local coords.*/ virtual bool computeWorldToLocalMatrix(Matrix& matrix,const Transform* transform, NodeVisitor* nv) const = 0; }; /** Set the ComputerTransfromCallback which allows users to attach * custom computation of the local transformation as seen by cull * traversers and the like. */ void setComputeTransformCallback(ComputeTransformCallback* ctc) { _computeTransformCallback=ctc; dirtyBound(); } /** Get the non const ComputerTransfromCallback.*/ ComputeTransformCallback* getComputeTransformCallback() { return _computeTransformCallback.get(); } /** Get the const ComputerTransfromCallback.*/ const ComputeTransformCallback* getComputeTransformCallback() const { return _computeTransformCallback.get(); } /** Get the transformation matrix which moves from local coords to * world coords. * Returns true if the Matrix passed in has been updated. */ inline bool getLocalToWorldMatrix(Matrix& matrix,NodeVisitor* nv) const { if (_computeTransformCallback.valid()) return _computeTransformCallback->computeLocalToWorldMatrix(matrix,this,nv); else return computeLocalToWorldMatrix(matrix,nv); } /** Get the transformation matrix which moves from world coords to * local coords. * Return true if the Matrix passed in has been updated. */ inline bool getWorldToLocalMatrix(Matrix& matrix,NodeVisitor* nv) const { if (_computeTransformCallback.valid()) return _computeTransformCallback->computeWorldToLocalMatrix(matrix,this,nv); else return computeWorldToLocalMatrix(matrix,nv); } virtual bool computeLocalToWorldMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_TO_PARENTS) { return false; } else // absolute { matrix.makeIdentity(); return true; } } virtual bool computeWorldToLocalMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_TO_PARENTS) { return false; } else // absolute { matrix.makeIdentity(); return true; } } protected : virtual ~Transform(); /** Overrides Group's computeBound. * There is no need to override in subclasses from osg::Transform * since this computeBound() uses the underlying matrix (calling * computeMatrix if required.) */ virtual bool computeBound() const; ref_ptr _computeTransformCallback; ReferenceFrame _referenceFrame; }; } #endif